1. Field of the Invention
The present invention relates to a system for inspecting chips, and more particularly, to a system for inspecting chips in a tray and a tray handling apparatus thereof.
2. Description of the Related Art
The requirements of high mobility and high performance for electronic devices are driving forces for progressing the integrated circuit packaging technology such that the compact packaging technologies such as COG (Chip on Glass) packaging have become more and more popular. When the COG packaging technology is applied, the chips are examined and processed in trays, and the equipment used in the COG packaging process must have tray handling and transporting capabilities.
Trays for receiving chips are generally available in sizes of 2, 3, and 4 inches. If trays of all three sizes are to be received, the tray handling apparatus must be adjustable to fit all of the sizes. FIG. 1 illustrates an adjusting mechanism of a prior art tray handling apparatus for accommodating trays of different sizes. As shown in FIG. 1, when smaller trays are to be used, the guides 101-104 must be adjusted to change the size of the space defined by the guides 101-104 to fit the size of the trays. When the prior art tray handling apparatus is adjusted, the guide 101 and the guide 102 are moved toward one another along the x-direction, and the guide 103 and the guide 104 are respectively moved along diagonal directions of the space until the size of the space fits the size of the tray. The guides 101-104 are moved independently so that the adjustment of the space is not convenient for a user. After the guides 101-104 are adjusted, the chuck 105 is misaligned with the center position of the bottom area of the adjusted space, and the position of the chuck 105 must be adjusted; otherwise it will not work properly. The misalignment problem is more serious when the space for a 4-inch tray is adjusted to the space for a 2-inch tray. Usually, the mechanism for adjusting the chuck position is inside the equipment and is difficult to access and manipulate by an operator.
Moreover, the differences in tray thickness also challenge the usability of the chuck device of a prior art equipment. The up-and-down movement of the chuck of a prior art equipment is driven by a pneumatic cylinder. Because the stroke of a pneumatic cylinder is fixed, the loading or unloading of trays with different thicknesses to or from the chuck may cause problems.
The present invention proposes a tray handling solution that can be easily adjusted and used for trays with different thicknesses, to resolve the above problems of the chip packaging industry.